Systems and methods for determining axial orientation and location of a user&#39;s wrist

ABSTRACT

The provided disclosure relates to systems and methods for determining the axial orientation and location of a user&#39;s wrist using one or more sensors located on the strap, the device underbody, or both. For example, the strap can include a plurality of elastic sections and a plurality of rigid sections. Each elastic section can include one or more flex sensors. In some examples, one or more electromyography (EMG) sensors can be included to measure the user&#39;s electrical signals, and the user&#39;s muscle activity can be determined. In some examples, a plurality of strain gauges can be included to generate one or more signals indicative of any changes in shape, size, and/or physical properties of the user&#39;s wrist. In some examples, the device can include a plurality of capacitance sensors for increased granularity and/or sensitivity in measuring the amount of tension exerted by the user&#39;s wrist.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/705,644, filed Sep. 15, 2017, and published on Mar. 22, 2018 as U.S.Patent Publication No. 2018-0078183 which claims the benefit under 35USC 119(e) of U.S. Patent Application No. 62/398,338, filed Sep. 22,2016, the contents of which are incorporated herein by reference intheir entirety for all purposes.

FIELD OF THE DISCLOSURE

This relates to systems and method for determining axial orientation andlocation of a user's wrist.

BACKGROUND OF THE DISCLOSURE

Mobile electronic devices, such as mobile phones, smart phones, tablecomputers, media players, and the like, have become quite popular. Manyusers carry a device almost everywhere they go and use their devices fora variety of purposes, including making and receiving phone calls,sending and receiving text messages and emails, navigation (e.g., usingmaps and/or a GPS receiver), purchasing items in a store (e.g., usingcontactless payment systems), and/or accessing the Internet (e.g., tolook up information).

A user's mobile device may not always be readily accessible. Forinstance, when a mobile device receives a phone call, the device may bein a user's bag or pocket, and the user may be walking, driving,carrying something, or involved in other activity that can make itinconvenient or impossible for the user to reach into the bag or pocketto find the device.

A wearable device can assist with accessibility of information from themobile device. In some examples, the user's movements can lead tofrequent changes in the configuration and/or orientation of the wearabledevice relative to the user's wrist. In some instances, measurementsregarding the user's mobility and functions can be skewed.

SUMMARY OF THE DISCLOSURE

This relates to systems and methods for determining the axialorientation and location of the user's wrist. The axial orientation andlocation can be determined using one or more sensors located on thestrap, the device underbody, or both. For example, the strap (attachedto the device underbody) can include a plurality of elastic sections anda plurality of rigid sections. Each elastic section can include one ormore flex sensors. The flex sensors can be sensors configured togenerate one or more signals indicative of the expansion or contractionsof the user's wrist due to extension or tension, for example. In someexamples, on or more electromyography (EMG) sensors can be included tomeasure the user's electrical signals, and the user's muscle activitycan be determined. Measurements from the EMG sensors can be used inconjunction with one or more other sensor measurements, such as PPGsensor measurements, to determine one or more user characteristics. Insome examples, a plurality of strain gauges (e.g., piezoelectricsensors) can be included to generate one or more signals indicative ofany changes in shape, size, and/or physical properties of the user'swrist. In some examples, the device can include a plurality ofcapacitance sensors for increased granularity and/or sensitivity inmeasuring the amount of tension exerted by the user's wrist. The systemsand methods disclosed can include analysis and feedback to a userregarding the user's performance (e.g., sports performance), noisereduction and/or cancellation, hydration detection for prolonged EMGsensor longevity, and user identification.

The wearable device can include a wristband or strap that canincorporate one or more sensors capable of determining the axialorientation of the user's wrist and/or capable of detecting changes inthe position of the wearer's wrist. In some examples, the sensors caninclude

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate systems in which examples of the disclosure canbe implemented

FIG. 2 illustrates an exemplary wearable device communicating wirelesslywith a host device according to examples of the disclosure.

FIG. 3 illustrates a block diagram of an exemplary wearable deviceaccording to examples of the disclosure.

FIG. 4A illustrates a perspective view of an exemplary wearable devicehaving a strap that can include a plurality of elastic sections and aplurality of rigid sections according to examples of the disclosure.

FIG. 4B illustrates a perspective view of an exemplary wearable devicehaving a strap including one or more electrodes embedded at leastpartially within one or more elastic sections according to examples ofthe disclosure.

FIG. 4C illustrates a perspective view of an exemplary wearable devicehaving a strap that can include strain gauge sensors according toexamples of the disclosure.

FIG. 5 illustrates an exemplary method for providing analysis andfeedback to a user regarding the user's sports performance according toexamples of the disclosure.

FIG. 6 illustrates a perspective view of an exemplary wearable devicehaving a strap that can include capacitive sensors according to examplesof the disclosure.

FIG. 7A illustrates a perspective view of an exemplary wearable devicehaving a strap that can include capacitive and EMG sensors according toexamples of the disclosure.

FIG. 7B illustrates a perspective view of an exemplary wearable devicehaving a strap that can include capacitive and sensors and a pluralityof elastic sections according to examples of the disclosure.

DETAILED DESCRIPTION

In the following description of examples, reference is made to theaccompanying drawings in which it is shown by way of illustrationspecific examples that can be practiced. It is to be understood thatother examples can be used and structural changes can be made withoutdeparting from the scope of the various examples.

Various techniques and process flow steps will be described in detailwith reference to examples as illustrated in the accompanying drawings.In the following description, numerous specific details are set forth inorder to provide a thorough understanding of one or more aspects and/orfeatures described or referenced herein. It will be apparent, however,to one skilled in the art, that one or more aspects and/or featuresdescribed or referenced herein may be practiced without some or all ofthese specific details. In other instances, well-known process stepsand/or structures have not been described in detail in order to notobscure some of the aspects and/or features described or referencedherein.

Further, although process steps or method steps can be described in asequential order, such processes and methods can be configured to workin any suitable order. In other words, any sequence or order of stepsthat can be described in the disclosure does not, in and of itself,indicate a requirement that the steps be performed in that order.Further, some steps may be performed simultaneously despite beingdescribed or implied as occurring non-simultaneously (e.g., because onestep is described after the other step). Moreover, the illustration of aprocess by its depiction in a drawing does not imply that theillustrated process is exclusive of other variations and modificationthereto, does not imply that the illustrated process or any of its stepsare necessary to one or more of the examples, and does not imply thatthe illustrated process is preferred.

This relates to systems and methods for determining the axialorientation and location of the user's wrist. The axial orientation andlocation can be determined using one or more sensors located on thestrap, the device underbody, or both. For example, the strap (attachedto the device underbody) can include a plurality of elastic sections anda plurality of rigid sections. Each elastic section can include one ormore flex sensors. The flex sensors can be sensors configured togenerate one or more signals indicative of the expansion or contractionsof the user's wrist due to extension or tension, for example. In someexamples, on or more electromyography (EMG) sensors can be included tomeasure the user's electrical signals, and the user's muscle activitycan be determined. Measurements from the EMG sensors can be used inconjunction with one or more other sensor measurements, such as PPGsensor measurements, to determine one or more user characteristics. Insome examples, a plurality of strain gauges (e.g., piezoelectricsensors) can be included to generate one or more signals indicative ofany changes in shape, size, and/or physical properties of the user'swrist. In some examples, the device can include a plurality ofcapacitance sensors for increased granularity and/or sensitivity inmeasuring the amount of tension exerted by the user's wrist. The systemsand methods disclosed can include analysis and feedback to a userregarding the user's performance (e.g., sports performance), noisereduction and/or cancellation, hydration detection for prolonged EMGsensor longevity, and user identification.

FIGS. 1A-1C illustrate systems in which examples of the disclosure canbe implemented. FIG. 1A illustrates an exemplary mobile telephone 136that can include a touch screen 124. FIG. 1B illustrates an exemplarymedia player 140 that can include a touch screen 126. FIG. 1Cillustrates an exemplary wearable device 144 that can include a touchscreen 128 and can be attached to a user using a strap 146. The systemsof FIGS. 1A-1C can utilize the systems and methods for determining axialorientation of the user's wrist, as will be disclosed.

FIG. 2 illustrates an exemplary wearable device communicating wirelesslywith a host device according to examples of the disclosure. Wearabledevice 200 can be a wristwatch-like device with face portion 204connected to strap 206. Face portion 204 can include, for example, atouchscreen display 205 that can be appropriately sized depending onwhere wearable device 200 is intended to be worn. The user can viewinformation presented by wearable device 200 on touchscreen display 205and can provide input to wearable device 200 by touching touchscreendisplay 205. In some examples, touchscreen display 205 can occupy mostor all of the front surface of face portion 204.

Strap 206 (also referred to herein as a wristband or wrist strap) can beprovided to allow device 200 to be removably worn (e.g., around theuser's wrist) by the user. In some examples, strap 206 can include aflexible material (e.g., fabrics, flexible plastics, leather, chainlinks, or flexibly interleaved plates or links made of metal or otherrigid materials) and can be connected to face portion 204 (e.g., byhinges, loops, or other suitable attachment devices or holders). In someexamples, strap 206 can be made of two or more sections of a rigidmaterial joined by clasp 208. One or more hinges can be positioned atthe junction of face 204 and proximal ends 212A and 212B of strap 206and/or elsewhere along the lengths of strap 206 (e.g., to allow a userto put on and take off wearable device 200). Different portions of strap206 can include different materials. For example, strap 206 can includeflexible or expandable sections alternating with rigid sections. In someexamples, strap 206 can include removable sections, allowing wearabledevice 200 to be resized to accommodate a particular user's wrist size.In some examples, strap 206 can include portions of a continuous strapmember that runs behind or through face portion 204. Face portion 204can be detachable from strap 206, permanently attached to strap 206, orintegrally formed with strap 206.

In some examples, strap 206 can include clasp 208 that can facilitatewith connection and disconnection of distal ends of strap 206. In someexamples, clasp 208 can include buckles, magnetic clasps, mechanicalclasps, snap closures, etc. In some examples, wearable device 200 can beresized to accommodate a particular user's wrist size. Accordingly,device 200 can be secured to a user's person (e.g., around the user'swrist) by engaging clasp 208. Clasp 208 can be subsequently disengagedto facilitate removal of device 200 from the user's person.

In some examples, strap 206 can be formed as a continuous band of anelastic material (including, for example, elastic fabrics, expandablemetal links, or a combination of elastic and inelastic sections),allowing wearable device 200 to be put on and taken off by stretching aband formed by strap 206 connecting to face portion 204. Thus, clasp 208may not be required.

Strap 206 (including any clasp that may be present) can include one ormore sensors that can allow wearable device 200 to determine whether thedevice is worn by the user at any given time. Wearable device canoperate differently depending on whether the device is currently beingworn or not. For example, wearable device 200 can inactivate varioususer interface and/or RF interface components when it is not being worn.In addition, in some examples, wearable device 200 can notify hostdevice 202 when a user puts on or takes off wearable device 200.Further, strap 206 can include sensors capable of detecting wristarticulations of a user.

Host device 202 can be any device that can communicate with wearabledevice 200. Although host device 202 is illustrated in the figure as asmart phone, examples of the disclosure can include other devices, suchas a tablet computer, a media player, any type of mobile device, alaptop or desktop computer, or the like. Other examples of host devicescan include point-of-sale terminals, security systems, environmentalcontrol systems, and so on. Host device 202 can communicate wirelesslywith wearable device 200 using, for example, protocols such as Bluetoothor Wi-Fi. In some examples, wearable device 200 can include electricalconnector 210 that can be used to provide a wired connection to hostdevice 202 and/or to other devices (e.g., by using suitable cables). Forexample, connector 210 can be used to connect to a power supply tocharge an onboard battery of wearable device 200.

In some examples, wearable device 200 and host device 202 caninteroperate to enhance functionality available on host device 202. Forexample, wearable device 200 and host device 202 can establish a pairingusing a wireless communication technology, such as Bluetooth. While thedevices are paired, host device 202 can send notifications of selectedevents (e.g., receiving a phone call, text message, or email message) towearable device 200, and wearable device 200 can present correspondingalerts to the user. Wearable device 200 can also provide an inputinterface via which a user can respond to an alert (e.g., to answer aphone call or reply to a text message). In some examples, wearabledevice 200 can also provide a user interface that can allow a user toinitiate an action on host device 202, such as unlocking host device 202or turning on its display screen, placing a phone call, sending a textmessage, or controlling media playback operations of host device 202.Techniques described herein can be adapted to allow a wide range of hostdevice functions to be enhanced by providing an interface via wearabledevice 200.

It will be appreciated that wearable device 200 and host device 202 areillustrative and that variations and modifications are possible. Forexample, wearable device 200 can be implemented in a variety of wearablearticles, including a watch, a bracelet, or the like. In some examples,wearable device 200 can be operative regardless of whether host device202 is in communication with wearable device 200; a separate host devicemay not be required.

Wearable device 200 can be implemented using electronic componentsdisposed within face portion 204 and/or strap 206. FIG. 3 illustrates ablock diagram of an exemplary wearable device according to examples ofthe disclosure. Wearable device 300 can include processing subsystem302, storage subsystem 304, user interface 306, RF interface 308,connector interface 310, power subsystem 312, device sensors 314, andstrap sensors 316. Wearable device 300 can also include other components(not explicitly shown)

Storage subsystem 304 can be implemented using, for example, magneticstorage media, flash memory, other semiconductor memory (e.g., DRAM,SRAM), or any other non-transitory storage medium, or a combination ofmedia, and can include volatile and/or non-volatile media. In someexamples, storage subsystem 304 can store media items such as audiofiles, video files, image or artwork files; information from a user'scontacts (e.g., names, addresses, phone numbers, etc.); informationabout a user's scheduled appointments and events; notes; and/or othertypes of information. In some examples, storage subsystem 304 can alsostore one or more application programs (or apps) 334 to be executed byprocessing subsystem 302 (e.g., video game programs, personalinformation management programs, media playback programs, interfaceprograms associated with particular host devices, and/or host devicefunctionalities, etc.).

User interface 306 can include any combination of input and outputdevices. A user can operate input devices of user interface 306 toinvoke the functionality of wearable device 300 and can view, hear,and/or otherwise experience output from wearable device 300 via outputdevices of user interface 306.

Examples of output devices can include display 320, speakers 322, andhaptic output generator 324. Display 320 can be implemented usingcompact display technologies (e.g., liquid crystal display (LCD),light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), orthe like). In some examples, display 320 can incorporate a flexibledisplay element or curved-glass display element, allowing wearabledevice 300 to conform to a desired shape. One or more speakers 322 canbe provided using small-form-factor speaker technologies, including anytechnology capable of converting electronic signals into audible soundwaves. In some examples, speakers 322 can be used to produce tones(e.g., beeping or ringing) and can but need not be capable ofreproducing sounds such as speech or music with any particular degree offidelity. Haptic output generator 324 can be, for example, a device thatcan convert electronic signals into vibrations. In some examples, thevibrations can be strong enough to be felt by a user wearing wearabledevice 300, but not so strong as to produce distinct sounds.

Examples of input devices can include microphone 326, touch sensor 328,and camera 329. Microphone 326 can include any device that convertssound waves into electronic signals. In some examples, microphone 326can be sufficiently sensitive to provide a representation of specificwords spoken by a user. In some examples, microphone 326 can be usableto provide indications of general ambient sound levels withoutnecessarily providing a high-quality electronic representation ofspecific sounds.

Touch sensor 328 can include, for example, a capacitive sensor arraywith the ability to localize contacts to a particular point(s) or regionon the surface of the sensor. In some examples, touch sensor 328 candistinguish multiple simultaneous contacts. In some examples, touchsensor 328 can be overlaid over display 320 to provide a touchscreeninterface (e.g., touchscreen interface 205 of FIG. 2), and processingsubsystem 302 can translate touch events (including taps and/or othergestures made with one or more contacts) into specific user inputsdepending on what is currently displayed on display 320.

Camera 329 can include, for example, a compact digital camera thatincludes an image sensor such as a CMOS sensor and optical components(e.g., lenses) arranged to focus an image onto the image sensor, alongwith control logic operable to use the imaging components to capture andstore still and/or video images. Images can be stored, for example, instorage subsystem 304 and/or transmitted by wearable device 300 to otherdevices for storage. Depending on implementation, the optical componentscan provide fixed focal distance or variable focal distance. In someexamples, with variable focal distance, autofocus can be provided. Insome examples, camera 329 can be disposed along an edge of the facemember (e.g., top edge of face portion 204 of FIG. 2) and oriented toallow a user to capture images of nearby objects in the environment,such as a bar code or QR code. In some examples, camera 329 can bedisposed on the front surface of face portion 204 (e.g., to captureimages of the user). Any number of cameras can be provided, depending onthe implementation.

In some examples, user interface 306 can provide output to and/orreceive input from an auxiliary device, such as a headset. For example,audio jack 330 can connect via an audio cable (e.g., a standard 2.5-mmor 3.5-mm audio cable) to an auxiliary device. Audio jack 330 caninclude input and/or output paths. Accordingly, audio jack 330 canprovide audio to and/or receive audio from the auxiliary device. In someexamples, a wireless connection interface can be used to communicatewith an auxiliary device.

Processing subsystem 302 can be implemented as one or more integratedcircuits (e.g., one or more single-core or multi-core microprocessors ormicrocontrollers). In operation, processing system 302 can control theoperation of wearable device 300. In some examples, processing subsystem302 can execute a variety of programs in response to program code andcan maintain multiple concurrently executing programs or processes. Atany given time, some or all of the program code to be executed can bestored in processing subsystem 302 and/or in storage media such asstorage subsystem 304.

Through suitable programming, processing subsystem 302 can providevarious functionality for wearable device 300. For example, processingsubsystem 302 can execute an operating system (OS) 332 and variousapplications 334 such as a phone-interface application, atext-message-interface application, a media interface application, afitness application, and/or other applications. In some examples, someor all of these application programs can interface with a host device,for example, by generating messages to be sent to the host device and/orby receiving and interpreting messages from the host device. In someexamples, some or all of the application programs can operate locally towearable device 300. For example, if wearable device 300 has a localmedia library stored in storage subsystem 304, a media interfaceapplication can provide a user interface to select and play locallystored media items. Processing subsystem 302 can also providewrist-gesture-based control, for example, by executing gestureprocessing code 335 (which can be part of OS 323 or provided separatelyas desired).

RF (radio frequency) interface 308 can allow wearable device 300 tocommunicate wirelessly with various host devices. RF interface 308 caninclude RF transceiver components, such as an antenna and supportingcircuitry, to enable data communication over a wireless medium (e.g.,using Wi-Fi/IEEE 802.11 family standards), Bluetooth, or other protocolsfor wireless data communication. RF interface 308 can be implementedusing a combination of hardware (e.g., driver circuits, antennas,modulators/demodulators, encoders/decoders, and other analog and/ordigital signal processing circuits) and software components. In someexamples, RF interface 308 can provide near-field communication (“NFC”)capability (e.g., implementing the ISO/IEC 18092 standards or the like).In some examples, NFC can support wireless data exchange between devicesover a very short range (e.g., 20 cm or less). Multiple differentwireless communication protocols and associated hardware can beincorporated into RF interface 308.

Connector interface 310 can allow wearable device 300 to communicatewith various host devices via a wired communication path, for example,using Universal Serial Bus (USB), universal asynchronousreceiver/transmitter (UART), or other protocols for wired datacommunication. In some examples, connector interface 310 can provide apower port, allowing wearable device 300 to receive power, for example,to charge battery 340. For example, connector interface 310 can includea connector such as a mini-USB connector or a custom connector, as wellas supporting circuitry. In some examples, the connector can be a customconnector that can provide dedicated power and ground contacts, as wellas digital data contacts that can be used to implement differentcommunication technologies in parallel. For example, two pins can beassigned as USB data pins (D+ and D−) and two other pins can be assignedas serial transmit/receive pins (e.g., implementing a UART interface).The assignment of pins to particular communication technologies can behardware or negotiated while the connection is being established. Insome examples, the connector can also provide connections for audioand/or video signals, which can be transmitted to or from host device302 in analog and/or digital formats.

In some examples, connector interface 310 and/or RF interface 308 can beused to support synchronization operations in which data can betransferred from a host device to wearable device 300 (or vice versa).For example, as described below, a user can customize certaininformation for wearable device 300 (e.g., settings related towrist-gesture control). While user interface 306 can support data-entryoperations, a user may find it more convenient to define customizedinformation on a separate device (e.g., a tablet or smartphone) that canhave a larger interface (e.g., including a real or virtual alphanumerickeyboard). The customized information can be transferred to wearabledevice via a synchronization operation. Synchronization operations canalso be used to load and/or update other types of data in storagesubsystem 304, such as media items, application programs, personal data,and/or operating system programs. Synchronization operations can beperformed in response to an explicit user request and/or automatically(e.g., when wearable device 200 resumes communication with a particularhost device or in response to either device receiving an update to itscopy of synchronized information).

Device sensors 314 can include various electronic, mechanical,electromechanical, optical, and/or other apparatus that can provideinformation related to external conditions around wearable device 300.Sensors 314 can provide digital signals to processing subsystem 303, forexample, on a streaming basis or in response to polling by processsubsystem 302 as desired. Any type and combination of device sensors canbe used. For example, device sensors 314 can include accelerometer 342,magnetometer 344, gyroscopic sensor 346, GPS (global positioning system)receiver 348, optical sensors 362, and barometric sensors 364. One ormore of device sensors 314 can provide information about the locationand/or motion of wearable device 300. For example, accelerometer 342 cansense acceleration (e.g., relative to freefall) along one or more axes,for example, using piezoelectric or other components in conjunction withassociated electronics to produce a signal. Magnetometer 344 can sensean ambient magnetic field (e.g., Earth's magnetic field) and cangenerate a corresponding electrical signal, which can be interpreted asa compass direction. Gyroscopic sensor 346 can sense rotational motionin one or more directions, for example, using one or moremicro-electro-mechanical systems (MEMS) gyroscopes and related controland sense circuitry. GPS receiver 348 can determine location based onsignals received from GPS satellites. Optical sensors 362 can sense oneor optical properties of light used, for examples, in determiningphotoplethsmyogram (PPG) information associated with the user. In someexamples, optical sensors 362 can include ambient light sensors (ALS) todetermine ambient light properties. Barometric sensors 364 can sense theatmospheric pressure to resolve vertical location information of thedevice.

Other sensors can also be included in addition to, or instead of, theseexamples. For example, a sound sensor can incorporate microphone 326together with associated circuitry and/or program code to determine, forexample, a decibel level of ambient sound. Temperature sensors,proximity sensors, ultrasound sensors, or the like can also be included.

Strap sensors 316 can include various electronic, mechanical,electromechanical, optical, or other devices that can provideinformation as to whether wearable device 300 is currently being worn,as well as information about forces that may be acting on the strap dueto movement of the user's wrist. Examples of strap sensors 316 aredescribed below. In some examples, signals from strap sensors 316 can beanalyzed, for example, using gesture processing code 336 to identifywrist gestures based on the sensor signals. Such gestures can be used tocontrol operations of wearable device 300.

Power subsystem 312 can provide power and power management capabilitiesfor wearable device 300. For example, power subsystem 312 can includebattery 340 (e.g., a rechargeable battery) and associated circuitry todistribute power from battery 340 to other components of wearable device300 that can require electrical power. In some examples, power subsystem312 can also include circuitry operable to charge battery 340, forexample, when connector interface 310 can be connected to a powersource. In some examples, power subsystem can include a “wireless”charger, such as an inductive charger, to charge battery 340 withoutrelying on connector interface 310. In some examples, power subsystem312 can also include other power sources (e.g., solar cell) in additionto, or instead of, battery 340.

In some examples, power subsystem 312 can control power distribution tocomponents within wearable device 300 to manage power consumptionefficiently. For example, power subsystem 312 can automatically placedevice 300 into a “hibernation” (or sleep/inactive) state when strapsensors 316 or other sensors indicate that device 300 is not being wornby the user. The hibernation state can be designed to reduce powerconsumption. For example, user interface 306 (or components thereof), RFinterface 308, connector interface 310, and/or device sensors 314 can bepowered down (e.g., to a low-power state or turned off entirely), whilestrap sensors 316 can be powered up (either continuously or atintervals) to detect when a user puts on wearable device 300. In someexamples, while wearable device 300 is being worn, power subsystem 312can turn display 320 and/or other components on or off depending onmotion and/or orientation of wearable device 300 detected by devicesensors 314. For instance, if wearable device 300 can be designed to beworn on a user's wrist, power subsystem 312 can detect raising androlling of the user's wrist, as is typically associated with looking atthe face of a wristwatch based on information provided by accelerometer342. In response to this detected motion, power subsystem 312 canautomatically turn display 320 and/or touch sensor 328 on. Similarly,power subsystem 312 can automatically turn display 320 and/or touchsensor 328 off in response to detecting that the user's wrist hasreturned to a neutral position (e.g., hanging down). As discussed below,in some examples, other sensors can be used to determine the axialorientation of the user's wrist for waking up (e.g., switching from aninactive state to an active state with higher power consumption) thewearable device or putting the device into a hibernation state.

Power subsystem 312 can also provide other power managementcapabilities, such as regulating power consumption of other componentsof wearable device 300 based on the source and amount of availablepower, monitoring and stored power in battery 340, generating useralerts if the stored power drops below a minimum level, etc.

In some examples, control functions of power subsystem 312 can beimplemented using programmable or controllable circuits operating inresponse to control signals generated by processing subsystem 302 inresponse to program code executing thereon, or as a separatemicroprocessor or microcontroller.

Examples of the disclosure can include variations and modifications tothe block diagram illustrated in FIG. 3. For example, strap sensors 316can be modified, and wearable device 300 can include a user-operablecontrol (e.g., a button or switch) that the user can operate to provideinput. Controls can also be provided, for example, to turn on or offdisplay 320, mute or unmute sounds from speakers 322, etc. Wearabledevice 300 can include any types and combination of sensors, and in someexamples, can include multiple sensors of a given type.

In some example, a user interface can include any combination of any orall of the components described above, as well as other components notexpressly described. For example, the user interface can include just atouch screen, or a touchscreen and a speaker, or a touchscreen and ahaptic device. Where the wearable device includes a RF interface, aconnector interface can be omitted, and all communication between thewearable device and other devices can be conducted using wirelesscommunication protocols. A wired power connection (e.g., for charging abattery of the wearable device) can be provided separately for any dataconnection.

Further, while the wearable device is described with reference tofunctional blocks, it is to be understood that these blocks are definedfor convenience of description and are not intended to imply aparticular physical arrangement of component parts. Further, the blocksneed not correspond to physically distinct components. Blocks can beconfigured to perform various operations (e.g., by programming aprocessor or providing appropriate control circuitry), and variousblocks might or might not be reconfigurable depending on how the initialconfiguration is obtained. Examples of the disclosure can be realized ina variety of apparatuses including electronic devices implemented usingany combination of circuitry and software. Furthermore, examples of thedisclosure are not limited to requiring every block illustrated in thefigure to be implemented in a given wearable device.

A host device (e.g., host device 202 of FIG. 2) can be implemented as anelectronic device using blocks similar to those described above (e.g.,processors, storage media, user interface devices, data communicationinterfaces, etc.) and/or other blocks or components. Any electronicdevice capable of communicating with a particular wearable device canact as a host device with respect to that wearable device. Communicationbetween a host device and a wireless device can be implemented accordingto any communication protocol (or combination of protocols) that bothdevices can be programmed or otherwise configured to use. In someexamples, such protocols (e.g., Bluetooth) can be used. In someexamples, a custom message format and syntax (including, for example, aset of rules for interpreting particular bytes or sequences of bytes ina digital data transmission) can be defined, and messages can betransmitted using standard serial protocols (e.g., a virtual serial portdefined in certain Bluetooth standards).

Examples of the disclosure can include systems and methods that canassist the user with determining and evaluating information related tothe user's wrist. In some examples, the exemplary wearable device can becapable of measuring the amount of tension in the user's wrist. FIG. 4Aillustrates a perspective view of an exemplary wearable device having astrap that can include a plurality of elastic sections and a pluralityof rigid sections according to examples of the disclosure. Wearabledevice 400 can include face member 402 and strap 404. Strap 404 can beconnected to face member 402 using strap holders 406 and 408 disposedalong top and bottom sides of face member 402. In some examples, strapholders 406 and 408 can be expandable strap holders.

In some examples, strap 404 can include a plurality of elastic sections405 interleaved with a plurality of rigid sections 407. Each elasticsection 405 can include one or more flex sensors (e.g., flex sensor 350illustrated in FIG. 3). The flex sensors can be sensors configured toexpand when the user's wrist extends, for example. In some example, theflex sensors can be configured to contract when the user's wrist hasmore tension. The flex sensors can include an elastic material (e.g.,elastic strap) or can include at least a partially embedded material. Anelectrical resistance can be measured across strap 404, the flexsensors, elastic section(s), and/or the partially embedded material.When strap 404 expands, an increase in electrical resistance can bemeasured; when strap 404 contracts, a decrease in electrical resistancecan be measured.

In some examples, elastic sections 405 can include one or moreelectrodes embedded at least partially within the elastic section, asillustrated in FIG. 4B. Electrodes 438 can be configured aselectromyography (EMG) sensors, which can sense muscle activity bymeasuring electrical activity. In some examples, electrodes 438 can bedisposed on elastic section 405 such that an exposed surface ofelectrodes 438 can contact the user's wrist (e.g., contacting the innerside of strap 404). In this manner, one elastic section 405 can becoupled to multiple measurement types, such as strain and EMG signals.

Measurements from the EMG sensors can be used in conjunction with one ormore other sensor measurements, such as PPG sensor measurements, todetermine one or more user characteristics. For example, the device canbe configured to determine the user's calorimetric expenditure using thedetermined muscle activity (related to the electrical activity measuredusing the EMG sensors) and the determined user's heart rate (related tothe blood oxygen activity measured using the PPG sensors).

In some examples, strap 404 can include a plurality of strain gauges, asillustrated in FIG. 4C. The plurality of strain gauges can include, forexample, piezoelectric sensors 452. Strap 404 can be secured around atleast a portion of the user's wrist. When the user's wrist moves, one ormore materials included in piezoelectric sensors 452 can change shape(e.g., deform) and/or any physical properties, and a signal (e.g.,voltage) proportional to the change in shape can be generated. In someexamples, each of the piezoelectric sensors 452 can be independentlycontrolled, which can give the device capability of determining thelocation of the tension.

Coupled with the signals(s) indicative of the amount of tension, one ormore strain “images” of the user's wrist can be generated. The strainimage can be a two dimensional representation of the location andintensity of tension. The strain image (or information from the straingauges) can be used at least in part to determine axial orientation ofthe wearable device on the user's wrist. For example, when a user gripshis or her hand, the bottom side (e.g., palm side) of the user's wristcan experience larger movement due to the tendons undergoing movementand being located closer to the bottom side. One or more strain gaugesthat experience greater strain (e.g., higher measured voltage) can beassociated with the location(s) of the user's tendon(s). From thisassociation, the axial orientation of the device can be determined.

In some examples, the strain gauges can be coupled with one or moreother types of sensors to provide analysis and user feedback. FIG. 5illustrates an exemplary method for providing analysis and feedback to auser regarding the user's performance according to examples of thedisclosure. The device can determine the axial orientation on the user'swrist (step 552 of process 550). The user can grip an instrument. Insome examples, the instrument can be a sports instrument (e.g., golfclub, baseball bat, etc.)(step 554 of process 550). The strain gaugescan be used to determine how tightly the user is gripping the sportsinstrument (step 556 of process 550). The user may then proceed tofollow through with a specific sports motion (e.g., swinging the golfclub or throwing a football) (step 558 of process 550). The motionsensors (e.g., accelerometer 342 or barometric sensors 364 of FIG. 3)can measure the user's performance in terms of, for example,acceleration, trajectory of the sports instrument, etc. (step 560 ofprocess 550). The device's controller can analyze the user's grip andperformance by comparing the measured and determined information toideal characteristics (e.g., stored in memory), for example (step 562 ofprocess 550). From the comparison, the device can provide a simulationof the user's performance and/or feedback to the user on how to improve(step 564 of process 550).

Although FIG. 5 illustrates an exemplary method for analysis of sportsperformance, examples of the disclosure can include analysis andfeedback for any type of user motion including gross motion (e.g., theuser brushing his or her hair) and fine motor motion (e.g., the usertyping on a keyboard). In some examples, if the user is moving orstirring more than a predetermined amount or if the user's tension isgreater than a predetermined amount, the strain gauges may be perturbedand measurements from the strain gauges may be inaccurate. One or moreEMG sensors can be configured to measure the tension of the user'swrist. Additionally, although FIG. 5 is discussed in the context ofstrain gauges used to determine the axial orientation, examples of thedisclosure can include other types of sensors, such as capacitivesensors discussed below.

In some examples, the exemplary wearable device can be capable ofmeasuring the amount of tension with increased granularity and/orsensitivity. FIG. 6 illustrates a perspective view of an exemplarywearable device having a strap that can include capacitive sensorsaccording to examples of the disclosure. Wearable device 600 can includeface member 602 and strap 604. Strap 604 can be connected to face member602 using strap holders 606 and 608 disposed along top and bottom sidesof face member 602.

Strap 604 can include a plurality of capacitance sensors 618. Pluralityof capacitance sensors 618 can be located on the inner side (i.e., sidefacing the underbody of the wearable device body) of strap 604. In someexamples, plurality of capacitance sensors 618 can also be located atleast partially on the outer side of strap 604. Plurality of capacitancesensors 618 can be configured to sense one or more changes incapacitance due to, for example, the increased (or decreased) capacitivecoupling as the user's wrist applies force to the electrodes. One ormore capacitance “images” of the user's wrist can be generated. Thecapacitance image can be a two-dimensional representation of thelocation and/or intensity of applied force. In some examples, pluralityof capacitance sensors 618 can include a grid (e.g., drive lines andsense lines arranged in rows and columns) of electrodes.

In some examples, strap holders 606 and 608 can include one or moreelectrical connections for transmitting signals from the one or moresensors (e.g., capacitance sensors 618) to the body (e.g., includingface member 602) of the wearable device. In some examples, some of thecapacitance sensors and/or other sensors (e.g., optical sensors) can beconfigured to couple (e.g., capacitively couple) to one or more sensorsincluded in the body. A processor or controller can be configuredutilize the coupling to transmit the signal(s) from the sensors includedin strap 704 to the body of wearable device 600.

FIG. 7A illustrates an exemplary wearable device having a strap that caninclude EMG and capacitive sensors according to examples of thedisclosure. Wearable device 700 can include face member 702 and strap704. Strap 704 can be connected to face member 702 using strap holders706 and 708 disposed along top and bottom sides of face member 702. Insome examples, strap holders 706 and 708 can be expandable strapholders.

Strap 704 can also include EMG sensors 738 and/or capacitance sensors718. EMG sensors 738 can include one or more electrodes configured tomeasure electrical activity. One or more signals indicative of themeasured electrical activity can be generated, and the user's muscleactivity can be determined from the signal(s). An exposed surface of EMGsensors 738 can contact the user's wrist (e.g., contacting the innerside of strap 704).

Capacitance sensors 718 can also be located on the inner side (i.e.,side facing the underbody of the wearable device body) of strap 704. Insome examples, plurality of capacitance sensors 718 can also be locatedat least partially on the outer side of strap 704. Plurality ofcapacitance sensors 718 can be configured to sense one or more changesin capacitance due to, for example, the increased (or decreased)capacitive coupling as the user's wrist applies force to the electrodes.One or more capacitance “images” of the user's wrist can be generated.The capacitance image can be a two dimensional representation of thelocation and/or intensity of applied force. In some examples, pluralityof capacitance sensors 718 can include a grid (e.g., drive lines andsense lines arranged in rows and columns) of electrodes.

In some examples, capacitance sensors 718 can be located on one side(e.g., top side) of strap 704, and EMG sensors 738 can be located on theother side (e.g., bottom side) of strap 704. Alternatively, capacitancesensors 718 can be interleaved with EMG sensors 738 (not shown).

In some examples, capacitance sensors 718 can be used for hydration(e.g., water and/or sweat) detection for prolonged EMG sensor longevity.When the capacitance sensors 718 detect the hydration, the device candisable or deactivate EMG sensors 738 to prevent from corrosion of theEMG sensors 738 when subject to hydration. The device can optionallyinform the user of the hydration conditions and can ask the user to drythe EMG sensors 738. When the capacitance sensors 718 detects a level ofhydration less than a predetermined level, the controller or processorcan allow activation of EMG sensors 738.

In some examples, strap 704 can include a plurality of elastic sections,as illustrated in FIG. 7B. Each elastic section 705 can include one ormore flex sensors (e.g., flex sensor 350 illustrated in FIG. 3). Theflex sensors can be sensors configured to expand when the user's wristextends, for example. In some example, the flex sensors can beconfigured to contract when the user's wrist has more tension. The flexsensors can include an elastic material (e.g., elastic strap) or caninclude at least a partially embedded material. An electrical resistancecan be measured across strap 704, the flex sensors, elastic section(s)705, and/or the partially embedded material. When strap 704 expands, anincrease in electrical resistance can be measured; when strap 604contracts, a decrease in electrical resistance can be measured.

In some examples, one or more of the elastic sections 705 can includeone or more EMG sensors 738 disposed on or embedded at least partiallywithin elastic sections 705. In this manner, one elastic section 705 canbe coupled to multiple measurement types, such as strain and EMGsignals. Moreover, the information from the strain and/or EMG signalscan be used in conjunction with information from one or more othersensors (e.g., capacitance sensors 718, optical sensors 362 illustratedin FIG. 3, piezoelectric sensors 452 illustrated in FIG. 4C,accelerometer 342 illustrated in FIG. 3, gyroscopic sensors 346illustrated in FIG. 3, magnetometer 344 illustrated in FIG. 3, and/orbarometric sensor 364 illustrated in FIG. 3) included in the strapand/or watch body to determine one or more user characteristics. Forexample, wearable device 700 can be capable of generating one or moreimages of the user's wrist. The images can include information such asamount and/or location of the user's tension (e.g., grip), axiallocation of the device on the user's wrist, motion and/or rotation ofthe user's wrist wearable device, vertical location of the user's wrist,and/or muscle activity of the user.

Another exemplary use of the systems and methods disclosed herein can befor weight training. For example, the user can be performing a bicepcurl. One or more motion sensors (e.g., accelerometer) can determiningthe timing of when the user can be performing the bicep curl. The motionsensors can associate the timing with the user's grip of the weights ordumbbells determined by the strain gauges (e.g., piezoelectric sensors).The timing of the bicep curl and user's grip can further be associatedwith the muscle activity determined by the EMG sensors. The timing ofthe bicep curl, the user's grip, and the muscle activity can optionallybe associated with the user's heart rate determined by, for example, thePPG (e.g., optical sensors) sensors. The device can analyze the user'sperformance and can provide feedback and/or, for example, calorimetricdata related to the user's weight lifting performance. For example, thedevice can inform the user that the user is over rotating his or herwrist during the exercise and/or is gripping the weights too tightly.

In addition to the one or more sensors disclosed above capable ofdetermining location and performance of the user's wrist, the one ormore sensors can give the wearable device capability of automaticallyself-calibrating the axial location and orientation. For example,instead of prompting the user, each time the wearable device is attachedto their wrist, for information regarding which wrist (e.g., left orright) the strap of the wearable device is secured around, the wearabledevice can determine such information from the one or more sensorsdisclosed above. For example, a user's left arm (attached to the user'sleft wrist) can have certain ranges of motion that the user's right arm(attached to the user's right wrist) cannot due to the limited bendingangles of each user's elbow joints). The wearable device can utilizeinformation from the EMG sensors, barometric sensors, and/or gyroscopicsensors, to discern between the user's left wrist and right wrist byassociating only certain ranges of motion with the user's left wrist andother ranges of motion with the user's right wrist. As another example,the wearable device can automatically detect whether the wearable devicebody is located on the palm side of the user's wrist using the flex,capacitance, and/or piezoelectric sensors based the location of theuser's tendons. In some examples, the device can self-calibrate when thedevice is first attached to the user's wrist (e.g., detected using theoptical and/or capacitance sensors), at certain predetermined intervals(e.g., every 30 minutes), and/or when one or more signal values change(e.g., by more than 10%).

Additionally or alternatively, the wearable device can use one or moresensors for noise reduction and/or cancellation. For example, adjacentEMG sensors 738 can experience the same amount of electrical activityfrom the user's muscles. If the signals from the adjacent EMG sensors738 vary (e.g., a non-zero differential exists), then a processor orcontroller can utilize the information to subtract, scale, or execute analgorithmic function to reduce or cancel the noise.

Examples of the disclosure can also include systems and methods that canallow a user to control the wireless device and/or host device usingmovements and/or axial orientation of the wrist. For example, thewearable device can be in communication with a television. The wearabledevice can recognize one or more gestures and/or sequences that a usercan perform as matching one or more predetermined gestures and/orsequences. The wearable device can execute and/or communicate a commandassociated with the predetermined gesture and/or sequence to commands(e.g., as a substitute for a remote control) to the television.

Examples of the disclosure can also include systems and methods that canbe used for authenticating and/or identifying the user based on one ormore properties of the user's wrist. Each user can have one or morewrist profiles (e.g., wrist size, tendon locations, wrist shape, etc.).When the user attaches the wearable device to the wrist, a processor orcontroller can match the wrist profile to a stored wrist profile. Thestored wrist profile can be associated with the user and can be used tounlock (i.e., give the user access to full range of functions) thedevice. In some examples, the stored wrist profiles can be used forrestoring calibration settings unique to the user and/or userpreferences.

A strap for a wearable device is disclosed. The strap can comprise: aninner side and an outer side; a plurality of strap holders configured toattach to a first edge and a second edge of a wearable device body; anda plurality of capacitance sensors located on the inner side of thestrap, the plurality of capacitance sensors configured to sense one ormore change in capacitance due to one or more forces of a user's wristcausing one or more changes in capacitance coupling, the plurality ofcapacitance sensors configured to generate one or more capacitancesignals indicative of the one or more changes in capacitance coupling.Additionally or alternatively, in some examples, the strap furthercomprises: a second plurality of capacitance sensors configured tocapacitively couple to the plurality of capacitance sensors and locatedon the outer side of the strap. Additionally or alternatively, in someexamples, the strap further comprises: a plurality of elastic sections,each elastic section including at least one flex sensor, wherein eachflex sensor is configured to contract when the user's wrist has moretension and generate one or more signals indicative of the contraction;and a plurality of rigid sections, one or more of the plurality ofelastic sections separated by one or more of the plurality of rigidsections. Additionally or alternatively, in some examples, the strapfurther comprises: a plurality of electromyography sensors configured tomeasure one or more electrical activities of the user's wrist.Additionally or alternatively, in some examples, the strap furthercomprises: a plurality of elastic sections, wherein the plurality ofelectromyography sensors are at least partially embedded in theplurality of elastic sections. Additionally or alternatively, in someexamples, the plurality of electromyography sensors is interleaved withthe plurality of capacitance sensors. Additionally or alternatively, insome examples, the strap further comprises: one or more piezoelectricsensors configured to measure one or more strains caused by the user'swrist. Additionally or alternatively, in some examples, the strapfurther comprises: one or more second capacitance sensors configured tocapacitively couple to one or more sensors located in a body of awearable device, wherein the logic is further configured to transmit theone or more capacitance signals to the body of the wearable device usingthe one or more second capacitance sensors. Additionally oralternatively, in some examples, the plurality of capacitance sensors isarranged as a grid of drive lines and sense lines.

A method of determining a performance of a wrist of a user is disclosed.The method can comprise: determining a tension of the wrist of the userusing one or more strain gauges; determining a motion of the wrist usingone or more of an accelerometer, gyroscopic sensors, and barometricsensors; and simulating the performance of the wrist using thedetermined tension and the determined motion. Additionally oralternatively, in some examples, the method further comprises: comparingthe simulated performance to a stored one or more ideal performances;and providing the simulation and a performance analysis to the user.Additionally or alternatively, in some examples, the performance isassociated with a sports performance and the tension of the wristincludes gripping a sports instrument.

A device is disclosed. The device can comprise: a device body includinga top side, an underside, a first edge, and a second edge; a displaylocated on the top side of the device body; a strap comprising: aplurality of strap holders configured to attach to the first and secondedges of the device body; an inner side and an outer side; a pluralityof strap holders configured to attach to a first edge and a second edgeof a wearable device body; a plurality of capacitance sensors located onthe inner side of the strap, the plurality of capacitance sensorsconfigured to sense one or more change in capacitance due to one or moreforces of a user's wrist causing one or more changes in capacitancecoupling, the plurality of capacitance sensors configured to generateone or more capacitance signals indicative of the one or more changes incapacitance coupling; and logic configured to: receive the one or morecapacitance signals, and generating one or more capacitance images ofthe user's wrist from the received on or more capacitance signals, theone or more capacitance images include a two-dimensional representationof location, intensity, or both of the one or more forces. Additionallyor alternatively, in some examples, the device is capable of automaticself-calibration, wherein self-calibration includes one or more ofdetermining an axial location and determining an axial orientation ofthe device body on the wrist of the user.

A method is disclosed. The method can comprise: determining one or moreaxial orientations of a device body on a wrist of a user, thedetermination comprising: activating one or more sensors to detect oneor more tendons of the user, determining a location of the one or moresensors on the device body or on a strap attached to the device body,and associating the one or more axial orientations to the determinationlocation; and determining one or more axial locations of the devicebody, the determination comprising: detecting a plurality of motions ofthe wrist of the user, comparing the detected plurality of motions toone or more stored ranges of motion, and associating the detectedplurality of motions to the one or more axial locations. Additionally oralternatively, in some examples, the method further comprises:determining one or more of a shape and a size of the wrist of the user;comparing the determined one or more shape and size of the wrist of theuser to one or more stored user profiles; and unlocking the device whenthe determined one or more shape and size of the wrist of the user matchthe one or more stored user profiles. Additionally or alternatively, insome examples, the method further comprises: restoring one or more ofcalibration settings and preferences unique to the user. Additionally oralternatively, in some examples, the determining the one or more axialorientations and the determining the one or more axial locations areautomatic. Additionally or alternatively, in some examples, the methodfurther comprises: detecting a coupling of the device body to the user,wherein the determining the one or more axial orientations and thedetermining the one or more axial locations are performed in response tothe detected coupling. Additionally or alternatively, in some examples,the method further comprises: detecting a change in one or more of theone or more axial orientations and one or more axial locations, whereinthe determining the one or more axial orientations and the determiningthe one or more axial locations are performed when an amount of thedetected change is greater than a predetermined amount.

Although examples have been fully described with reference to theaccompanying drawings, it is to be noted that various changes andmodifications will become apparent to those skilled in the art. Suchchanges and modifications are to be understood as being included withinthe scope of the various examples as defined by the appended claims.

The invention claimed is:
 1. A method of determining a performance of awrist of a user, the method comprising: measuring a tension of the wristof the user using one or more sensors included in a device; measuring amotion of the wrist using one or more of an accelerometer, a gyroscopicsensor, or a barometric sensor included in the device; determining theperformance of the wrist using the measured tension and the measuredmotion; determining a type of the performance; accessing one or morestored performances corresponding to the type of the performance;analyzing the performance by comparing the performance to the one ormore stored performances; and providing feedback to the user, thefeedback generated from analyzing the performance and configured to showdifferences between the performance and the one or more storedperformances.
 2. The method of claim 1, wherein: the performance isassociated with an action performed during a sport; and the tensioncorresponds to a grip of a sports instrument.
 3. The method of claim 2,wherein: the sports instrument is a dumbbell; and the action is liftingthe dumbbell.
 4. The method of claim 2, wherein: the one or more sensorsinclude piezoelectric sensors; and measuring the tension of the wristcomprises: receiving one or more signals in response to a change inproperties of one or more materials included in the piezoelectricsensors; and determining the tension of the wrist based on the one ormore signals.
 5. The method of claim 4, further comprising determining alocation of the tension by separately receiving and analyzing each ofthe one or more signals.
 6. The method of claim 1, further comprising:determining a timing of the motion of the wrist; and associating thetiming to the tension, wherein the feedback incorporates the timing. 7.The method of claim 6, further comprising: determining a muscle activityassociated with the motion using one or more electromyography sensors;and associating the timing and the tension with the muscle activity,wherein the feedback further incorporates the muscle activity.
 8. Themethod of claim 6, further comprising: determining a heart rate of theuser using one or more optical sensors included in the device; andassociating the heart rate with the timing and the tension.
 9. Themethod of claim 1, wherein the feedback includes suggestions on how toimprove the performance of the user.
 10. The method of claim 1, wherein:the motion of the wrist comprises a series of movements corresponding toa specific sports motion; and the specific sports motion includes one ormore of swinging a golf club, throwing a football, and lifting adumbbell.
 11. The method of claim 1, where the feedback includessimulating one or more of an acceleration of the wrist and a trajectoryof a sports instrument.
 12. The method of claim 1, further comprisingdetermining whether the device is located on a left wrist of the user ora right wrist of the user, wherein the determination of whether thedevice is located on the left wrist or the right wrist comprises:associating a range of motion with the left wrist and associatinganother range of motion with the right wrist; and determining whetherthe determined motion of the user matches the range of motion of theleft wrist or the another range of motion of the right wrist.
 13. Themethod of claim 1, wherein the measurement of the tension of the wristincludes: measuring a change in electrical resistance; and determiningwhether the wrist is expanding or contracting based on the change inelectrical resistance.
 14. The method of claim 1, wherein: the one ormore sensors include capacitance sensors; and the measurement of thetension of the wrist includes: sensing one or more changes incapacitance using the one or more sensors; and determining whether thewrist is expanding or contracting based on the changes in capacitance.15. A method comprising: determining one or more axial orientations of adevice body on a wrist of a user by activating one or more sensors tomeasure a tension of the wrist; determining one or more axial locationsof the device body by activating the one or more sensors to measure amotion of the wrist; determining a performance of the wrist using theone or more axial orientations and the one or more axial locations;determining a type of the performance; accessing a stored performancecorresponding to the type of the performance; comparing the performanceto the stored performance; and providing feedback to the user, thefeedback generated by comparing the performance to the storedperformance and configured to show differences between the performanceand the stored.
 16. The method of claim 15, further comprising:determining one or more of a shape and a size of the wrist of the user;comparing the determined one or more shape and size of the wrist of theuser to one or more stored user profiles; and unlocking the device whenthe determined one or more shape and size of the wrist of the user matchthe one or more stored user profiles.
 17. The method of claim 16,further comprising restoring one or more of calibration settings andpreferences unique to the user.
 18. The method of claim 15, wherein thedetermining the one or more axial orientations and the determining theone or more axial locations are performed automatically.
 19. The methodof claim 15, further comprising detecting a coupling of the device bodyto the user, wherein the determining the one or more axial orientationsand the determining the one or more axial locations are performed inresponse to the detected coupling.
 20. The method of claim 15, furthercomprising detecting a change in one or more of the one or more axialorientations and one or more axial locations, wherein the determiningthe one or more axial orientations and the determining the one or moreaxial locations are performed when an amount of the detected change isgreater than a predetermined amount.